102 lines
2.9 KiB
Markdown
102 lines
2.9 KiB
Markdown
---
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title: Hash from two arrays
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id: 595671d4d2cdc305f0d5b36f
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challengeType: 5
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forumTopicId: 302283
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---
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## Description
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<section id='description'>
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Using two Arrays of equal length, create a Hash object where the elements from one array (the keys) are linked to the elements of the other (the values).
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<strong>Related task:</strong>
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<ul>
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<li><a href="https://rosettacode.org/wiki/Associative arrays/Creation" title="Associative arrays/Creation" target="_blank">Associative arrays/Creation</a></li>
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</ul>
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</section>
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## Instructions
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<section id='instructions'>
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</section>
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## Tests
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<section id='tests'>
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```yml
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tests:
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- text: <code>arrToObj</code> is a function.
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testString: assert(typeof arrToObj === 'function');
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- text: '<code>arrToObj([1, 2, 3, 4, 5], ["a", "b", "c", "d", "e"])</code> should return <code>{ 1: "a", 2: "b", 3: "c", 4: "d", 5: "e" }</code>'
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testString: assert.deepEqual(arrToObj(...testCases[0]), res[0]);
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- text: '<code>arrToObj([1, 2, 3, 4, 5], ["a", "b", "c", "d"])</code> should return <code>{ 1: "a", 2: "b", 3: "c", 4: "d", 5: undefined }</code>'
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testString: assert.deepEqual(arrToObj(...testCases[1]), res[1]);
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- text: '<code>arrToObj([1, 2, 3], ["a", "b", "c", "d", "e"])</code> should return <code>{ 1: "a", 2: "b", 3: "c" }</code>'
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testString: assert.deepEqual(arrToObj(...testCases[2]), res[2]);
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- text: '<code>arrToObj(["a", "b", "c", "d", "e"], [1, 2, 3, 4, 5])</code> should return <code>{ "a": 1, "b": 2, "c": 3 , "d": 4, "e": 5 }</code>'
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testString: assert.deepEqual(arrToObj(...testCases[3]), res[3]);
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- text: '<code>arrToObj(["a", "b", "c", "d", "e"], [1, 2, 3, 4])</code> should return <code>{ "a": 1, "b": 2, "c": 3 , "d": 4, "e": undefined }</code>'
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testString: assert.deepEqual(arrToObj(...testCases[4]), res[4]);
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- text: '<code>arrToObj(["a", "b", "c"], [1, 2, 3, 4, 5])</code> should return <code>{ "a": 1, "b": 2, "c": 3 }</code>'
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testString: assert.deepEqual(arrToObj(...testCases[5]), res[5]);
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```
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</section>
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## Challenge Seed
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<section id='challengeSeed'>
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<div id='js-seed'>
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```js
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function arrToObj (keys, vals) {
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// Good luck!
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return true;
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}
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```
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</div>
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### After Test
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<div id='js-teardown'>
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```js
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const testCases = [
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[[1, 2, 3, 4, 5], ['a', 'b', 'c', 'd', 'e']],
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[[1, 2, 3, 4, 5], ['a', 'b', 'c', 'd']],
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[[1, 2, 3], ['a', 'b', 'c', 'd', 'e']],
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[['a', 'b', 'c', 'd', 'e'], [1, 2, 3, 4, 5]],
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[['a', 'b', 'c', 'd', 'e'], [1, 2, 3, 4]],
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[['a', 'b', 'c'], [1, 2, 3, 4, 5]]
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];
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const res = [
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{ 1: 'a', 2: 'b', 3: 'c', 4: 'd', 5: 'e' },
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{ 1: 'a', 2: 'b', 3: 'c', 4: 'd', 5: undefined },
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{ 1: 'a', 2: 'b', 3: 'c' },
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{ a: 1, b: 2, c: 3, d: 4, e: 5 },
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{ a: 1, b: 2, c: 3, d: 4, e: undefined },
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{ a: 1, b: 2, c: 3 }
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];
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```
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</div>
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</section>
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## Solution
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<section id='solution'>
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```js
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function arrToObj (keys, vals) {
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return keys.reduce((map, key, index) => {
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map[key] = vals[index];
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return map;
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}, {});
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}
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```
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</section>
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